void Particle::integrate(fseconds duration, int type) { // Defaults to Euler
// don't move objects that have "infinite mass."
if (invMass <= 0.0f) {
return;
}
// Universal properties
//lastPos = pos; // Only necessary for position Verlet
vec3 resultantAcc = acc + (invMass * accumulatedForces);
auto dt = duration.count();
if ( type == 1 ) { // Euler
// update position using Euler integration
pos = pos + dt * vel;
// update velocity using Euler integration
vel = vel + dt * resultantAcc;
// incorporate damping
vel = vel * std::pow(damping, dt);
} else if ( type == 2 ) { // RK
// Pop RK4 in here at some point because... why not
} else { // Velocity Verlet
pos = pos + ( vel * dt ) + ( 0.5f * resultantAcc * dt * dt );
// Assumes acc doesn't change between steps - still need to solve for acc+1 to be accurate if a changes
vel = vel + ( 0.5f * 2 * resultantAcc ) * dt;
}
clearForces();
}
void Particle::integrate(fseconds duration) {
// don't move objects that have "infinite mass."
if (invMass <= 0.0f) {
return;
}
//update velocity using Verlet
vel = vel + 1.0f/2.0f*acc*duration.count();
// update position using Velocity Verlet
pos = pos + vel * duration.count();
vec3 resultantAcc = (pos+duration.count())-(2.0f*pos+pos)-(duration.count());
// update velocity using Velocity Verlet
vel = vel + 1.0f/2.0f*resultantAcc*duration.count();
// incorporate damping
vel = vel * damping;
clearForces();
}
void Particle::integrate(fseconds duration) {
// don't move objects that have "infinite mass."
if (invMass <= 0.0f) {
return;
}
// update position using Euler integration
pos = pos + duration.count() * vel;
vec3 resultantAcc = acc;
resultantAcc = resultantAcc + (invMass * accumulatedForces);
// update velocity using Euler integration
vel = vel + duration.count() * resultantAcc;
// incorporate damping
vel = vel * damping;
clearForces();
}